The present invention relates to apparatus for the explosive decompression of biological material, and to a method of explosive decompression of biological material. More specifically, the apparatus and method relate to the explosive decompression of biological material resulting in a product that is homogenous in size.
Various methods of disrupting cell walls of biological material are known, the method (and associated apparatus) depending on whether the cell walls are rigid, elastic, neither, or do not exist. For example, sonic disruption of cells is used on non-rigid materials. However this is not effective on cells with rigid cell walls.
Mechanical methods for disrupting cells of biological material, such as grinding or milling, are also used. However, such methods have two possible disadvantages. Firstly, hot spots can develop in the material being ground or the temperature of the material increases. If proteins or enzymes are the desired product from the biological material, such heat (whether general or localised) can seriously degrade or render the desired products inactive. Secondly, on some cells, particularly botanical cells with very strong cell walls, this method does not always rupture the cell wall.
Methods using the application of a magnetic or electromagnetic field to the cells are also capable of disrupting cell walls. However this method is not always commercially reliable or versatile.
A further, known method of cellular disruption is that as discussed in WO 97/05787 (Ashourian). This publication discloses the use of an homogeniser to homogenize fruit cells within a puree or fluid or to produce same to reduce the size of cell components under pressure. However, the disruption is disclosed as producing a puree or an homogenised fluid. The process appears to be inapplicable to intra-cellular disruption of particulate material.
In all the above methods of cell wall disruption the result is a rip or tear in the cell wall. This is not always a break or disruption of sufficient size to release the contents of the cell for easy access to the cytoplasm and intact nucleus and organelles. Further, the above methods do not result in an homogenous mixture.
An object of the present invention is the provision of apparatus and a method for the production of a mixture containing disrupted biological material. A further object of the invention is the provision of such apparatus and method which overcome the disadvantages of known methods of disruption of biological material as described above, with reference to cells with rigid cell walls or non-rigid and non-elastic cell walls.
For the purposes of this specification xe2x80x9cbiological materialxe2x80x9d includes but is not limited to: cells with cell membranes, cells with rigid cell walls, cells with non-elastic, non-rigid cell walls, non-cellular biological material, intra-cellular material, unbounded homogenous material, and a combination thereof; all material being biological material that is, or can be, rendered particulate in appearance.
The present invention provides a method of disrupting biological material, said method including the steps of:
drying particulate biological material;
mixing said particulate material with a gas at a pressure between 4 and 800 bar and allowing said mixing to continue until gas penetration of some or all of the particulate material is effected;
releasing the pressure explosively and reducing the pressure of the particulate material to atmospheric at a temperature of not more than 400xc2x0 C.;
collecting the resultant product.
The present invention further provides a method of disrupting biological material, said method including:
drying particulate biological material;
mixing said particulate material with a gas at a pressure between 4 and 800 bar and allowing said mixing to continue until gas penetration of some or all of the particulate material is effected, wherein said particulate material is mixed in small portions;
separating a small portion of mixed material and gas and releasing the pressure explosively and reducing the pressure within the small portion of the particulate material to atmospheric at a temperature of not more than 400xc2x0 C.;
collecting the resultant product; and
repeating the above three steps, said repetition being in the nature of a continuous process.
Preferably the above methods produce a homogenous mixture of pieces and cytoplasm. Preferably the methods further include, after the step of releasing the pressure explosively, the step of allowing the explosively decompressed material to impact on or along a shear cone or wall.
Preferably the pressure is in the range 4 and 30 bar pressure.
Preferably the gas is selected from the group consisting of: air, carbon dioxide, nitrogen, helium, hydrogen, argon, neon, helium; and a combination of these. The selection of the gas used is dependent on the material to be processed, as the gas needs to be substantially inert with reference to that material. The selection is also dependent on commercial availability and cost of the gas(es). Preferably the time period for release of the pressure is less than one second, and more preferably 0.1 second.
Preferably, the gas penetration of the particulate material has reached an equilibrium before the pressure is explosively released. In the instance of particulate material with cell walls, this equilibrium occurs when the gas is in equilibrium within the cell wall. This time is generally between 1 to 10 minutes. However, more time may be used for this step of the method. Optionally the time for this step is between 1 and 3 minutes.
Preferably the particulate material is initially of a size between 0.1 to 2000 xcexcm, more preferably 0.1 to 50 xcexcm, and most preferably 0.1 to 20 xcexcm. With this range of particle sizes it can be seen that particles the size of bacteria, viruses, procaryotic, eucaryotic cells and cellular inclusions can be the biological material.
The biological material can be selected from the group including: material with rigid cell walls, cells with non-elastic, non-rigid cell walls, cells with cellular membranes, non-cellular biological material. Examples of such material include pollens, spirulina and other rigid cell walled unicellular species. The biological material can be biological material with non-rigid cell walls at room temperature which walls become rigid walls or non-elastic, non-rigid walls under extremely low temperatures. Examples of intra-cellular material or non-cellular material include organelles and nuclei, and shark cartilage. An example of such material with cell membranes is green lipped mussel powder.
The temperature range in which the above methods can be performed is xe2x88x92200xc2x0 to 400xc2x0 C., more preferably xe2x88x92196xc2x0 to 40xc2x0 C., and most preferably xe2x88x9215xc2x0 to 30xc2x0 C.
Optionally said methods produce a resultant product with a reduced count of biological contaminants, as compared with that of the starting particulate material, when the starting material is non-fungal material. The method optionally further includes the step of treating the resultant product with ultra-violet light.
Optionally, when the starting material is fungal, said methods produce a resultant product with an increased cell-forming count.
The present invention further provides apparatus for the disruption of biological material (as hereinbefore defined), said apparatus including:
a chamber with a first inlet means for particulate material and a second inlet means for gases and an outlet means for gases and material, said chamber being capable of withstanding pressures up to 800 bar; and
collection means attached to said outlet means;
wherein said outlet means includes a valve which is capable of releasing the pressure within the chamber in one second or less.
The present invention further provides apparatus for the disruption of biological material (as hereinbefore defined); said apparatus including:
a chamber with a first inlet means for particulate material and a second inlet means for gases and an outlet means for gases and material, said chamber being capable of withstanding pressures up to 800 bar;
collection means attached to said outlet means; wherein
said inlet means for particulate material includes two valves (an inner and an outer valve), each independently operated by an actuator, said valves being separated by an inlet chamber which is capable of withstanding pressures of up to 800 bar;
said outlet means for gases and material includes two valves (an inner and an outer) each independently operated by an actuator, said valves being separated by an outlet chamber which is capable of withstanding pressures of up to 800 bar;
wherein the outlet valve of the outlet means is capable of releasing the pressure within the outlet chamber in one second or less.
The present invention further provides apparatus for the disruption of biological material (as hereinbefore defined), said apparatus including:
a chamber with a first inlet means for particulate material and a second inlet means for gases and an outlet means for gases and material, said chamber being capable of withstanding pressures up to 800 bar;
collection means attached to said outlet means; wherein
said inlet means for particulate material includes one valve operated by an actuator;
said outlet means for gases and material includes two valves (an inner and an outer) each independently operated by an actuator, said valves being separated by an outlet chamber which is capable of withstanding pressures of up to 800 bar;
wherein the outlet valve of the outlet means is capable of releasing the pressure within the outlet chamber in one second or less.
Preferably said apparatus operates to produce a homogenous mixture of cell wall pieces and cytoplasm.
Preferably said apparatus also includes means to vibrate said chamber to facilitate the mixing of the particulate material and the gas. The collection means may be any known means of collecting fine particles, for example: a cyclone dust collector, a dust bag, an electrostatic dust precipitator and a combination of these. Preferably the collection means collects the exploded material under inert or substantially inert conditions.
Preferably the collection means further includes a cone placed within the collection means adjacent the outlet from the outlet valve of the outlet chamber; the position of the cone being such that the particulate material is still travelling at considerable speed, as a result of the explosive decompression, when the material impacts the cone and slides into the collection means.
Preferably, any of the embodiments of the apparatus operate in the pressure range 4 to 30 bar pressure.
Optionally, any of the embodiments of the apparatus can be operated under axenic conditions. Optionally the above-described apparatus can operated at temperatures in the range xe2x88x92200xc2x0 to 400xc2x0 C. more preferably xe2x88x92196xc2x0 to 40xc2x0 C. and most preferably xe2x88x9215xc2x0 to 30xc2x0 C.